AROMA COMPOUND RECOVERY WITH PERVAPORATION - FEED FLOW EFFECTS

A multi component aroma model, consisting of five organic model components in a dilute water solution, was pervaporated through polydimethylsiloxane membranes using different crossflow velocities and hydraulic diameters. Strong feed flow effects were observed in the laminar flow regime for model compounds with low membrane resistance and high concentrations in the feed. In the turbulent flow regime only small or no feed flow effects were observed. A model based on the resistance-in-series model and Sherwood correlations could describe this phenomenon. The different flux increments with increasing crossflow velocity for the different model compounds could be used as a tool, to some extent, to control the composition of the permeate.